Police are yet to fully implement any recommendations made about their processes following the death of Nicky Stevens in Hamilton early last year.
The 21-year-old drowned in the Waikato River, after being let out on an unsupervised smoking break, while under a compulsory care order in a mental health unit at Waikato Hospital.
Mr Stevens had a history of self-harm and was a patient at the Henry Rongomau Bennett Centre when he went missing.
Police were heavily criticised for their response to the case.
In May their watchdog, the Independent Police Conduct Authority (IPCA), recommended a review of the data entry process for creating missing person files, and an update of Communications Centre policy on missing persons.
Half a year on, police say work is still underway to implement both recommendations.
Nicky Stevens father, Dave Macpherson, said it felt like the case had been put on the backburner.
"It's really disappointing, from our family's point of view, that we heard the police say 'We're getting onto this straight away and here's what we've already started doing' and now it really does seem they're dragging the chain."
Mr Macpherson said the family was expecting to be brought in to help make improvements but hadn't officially heard from an officer in four months.
"We were expecting to be called in by the police in charge of the Northern comms centre, who mishandled the call about our son Nicky. And we were expecting to be called in to have discussions with the police that handle those reports when they come back... to try to give them a flavour of what the affected public is feeling, so they can sharpen up or improve the way they relate to families."
Mr Macpherson said the IPCA had compiled an excellent report and the family's time had been wasted.
"Good intentions don't cut the mustard when peoples' lives are at stake."
The IPCA chair, Judge Sir David Carruthers, told RNZ he was keeping tabs on progress.
"I promised the family we'd be back in touch with them, so the first thing for us is to check with the police about where those recommendations have got to, and what's happened, then we can tell the family."
Police won't disclose the disciplinary action they've taken in relation to the case, saying it was confidential, but a spokesperson confirmed the employment investigation had been finalised.
Mr Macpherson said he was unhappy police wouldn't give those details to the family.